I. Field of the Invention
This invention relates to fitted covers for mattresses and, in particular, to a fitted sheet which has additional elastic members for retaining the ends of the sheet over the corners of the mattress.
II. Description of the Prior Art
Contoured or fitted sheets for mattresses are well known to hold the sheet in place upon the mattress while eliminating wrinkles. Generally, contour sheets include a fabric body with end and side portions which are joined along a common edge to conform the sheet to the shape of the mattress. In order to properly retain the sheet upon the mattress, an elastic material may be secured to the edge of the sheet. In most instances, the elastic is sewn in the corners of the sheets such that the corners are maintained beneath the mattress. However, the elastic may be provided along the entire edge of the sheet in order to draw the edges of the sheet together beneath the mattress. In either prior known embodiment, the sheet is maintained on the mattress by the limited size of the opening formed by the edge of the sheet drawn together by the elastic.
However, repeated removal, washing and replacement of the fitted sheet causes the elastic to lose its elastic properties. This can cause the sheet to lose its contour and to be inadvertently removed from the mattress during normal use. Moreover, the simple elastic provided on the prior known fitted sheets is incapable of properly retaining the sheet on oversized or non-conventional mattresses such as waterbed mattresses which are subject to constant movement due to the fluid motion of the mattress.